Methods for concomitant treatment of theophylline and febuxostat

ABSTRACT

Co-administration of febuxostat and theophylline to a hyperuricemic patient suffering from gout is disclosed.

RELATED APPLICATION INFORMATION

This is a continuation of U.S. patent application Ser. No. 13/227,828, filed on Sep. 8, 2011, which claims priority to U.S. Provisional Patent Application No. 61/381,482, filed on Sep. 10, 2010, the contents of all of which are herein incorporated by reference in their entirety.

FIELD

The present disclosure relates to novel methods for treating hyperuricemia in patients also requiring treatment with theophylline. Specifically, the invention is directed to a method of administering theophylline in conjunction with one or more xanthine oxidoreductase inhibitors, whereby the xanthine oxidoreductase inhibitors do not cause alterations in the plasma concentrations of theophylline.

BACKGROUND

A substantial number of patients are affected with diseases of the respiratory system, including asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, and neonatal bradycardia. One of the primary treatments for respiratory diseases is the use of theophylline

Theophylline is a useful medicine frequently used as an agent for treating symptoms of bronchial asthma. It is known in the art that effective blood concentrations range from about 10 to 20 μg/ml. However, if the concentration of theophylline in the blood exceeds 20 μg/ml, serious side effects sometimes appear with regard to the cardiovascular system and the central nervous system. Further, there is a large difference in blood levels among individuals. Various conditions (e.g., cardiac insufficiency, liver and kidney disease, etc.), age differences, smoking, etc. also have large effects. Additionally, theophylline has a short biological half-life of about 6 hours for adults. In order to maintain the effective blood level, four doses per day have been considered necessary. However, such frequent dosing is troublesome to patients, reduces patient compliance, and causes the state of the disease to become worse. In particular, attacks of bronchial asthma often occur at daybreak. It is not possible to sufficiently prevent such attacks with ingestion of theophylline just before going to bed, and therefore, repeat ingestion close to daybreak is necessary. Thus, in the past, continuous effort has been made to develop a sustained release type theophylline formulation. Several formulations are already available on the market.

Another disease that affects a substantial number of patients is gout. Gout affects 3 to 5 million individuals in the United States of America (USA) and is increasing in incidence and prevalence. Gout is a serious health condition characterized by flares of acute arthritis, chronic gouty arthropathy, tophi, and uric acid urolithiasis, and is associated with a broad range of comorbidities, including cardiovascular disease, chronic kidney disease, and metabolic syndrome. At the joint level, a gout flare is best characterized as an acute monoarthritis arthropathy process with proliferative bone reaction that can affect any joint and that can later develop into chronic polyarthritis. Gout attacks tend to occur mostly in the lower extremities and over time additional joints can be involved.

The underlying metabolic aberration in gout is hyperuricemia, which is a condition defined as an elevation in serum urate (sUA) level ≧6.8 m/dL. Hyperuricemia develops into gout when urate crystals are formed from supersaturated body fluids and deposited in joints, tophi, and parenchymal organs due to a disorder in the urate metabolism. Uric acid is the end product of purine metabolism and is generated in the cascade of hypoxantine→xanthine→uric acid.

Urate-lowering therapy (ULT) is used to treat hyperuricemia in subjects with gout. The goal of ULT is to reduce sUA to 6.0 mg/dL or less, below the concentration at which monosodium urate saturates extracellular fluid. Using ULT to reduce and maintain sUA levels <6.0 mg/dL ultimately improves the clinical symptoms of gout by reducing the frequency of gout flares, decreasing size and number of tophi, and improving quality of life. One alternative that may be used for the treatment of gout is the administration of xanthine oxidase inhibitors, such as allopurinol. Generally, allopurinol is considered one of the primary treatments of gout and has developed wide usage as a treatment for gout.

However, clinicians have few treatment options for hyperuricemic patients also suffering from respiratory diseases, such as chronic obstructive pulmonary disease, asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, and neonatal bradycardia. One of the primary treatments for these respiratory diseases is the administration of theophylline, a bronchodilator. Although theophylline provides a treatment for the respiratory diseases described herein, the therapeutic range of theophylline blood concentrations is thought to be very narrow, ranging from about 10 to about 20 μg/ml. As such, if the theophylline dosing does not provide a minimum blood concentration of 10 μg/ml, the patient is not provided significant relief from the respiratory condition, and at blood concentrations greater than 20 μg/ml, the patient may be susceptible to adverse effects such as abdominal pain, headache, muscle cramps, tremors, tachycardia, and seizures. Therefore, clinicians must exercise caution in determining treatment options for patients requiring theophylline treatment, and must closely monitor the potential for drug interactions that may increase or decrease theophylline blood concentrations.

It is further known within the art that the administration of allopurinol interacts with the metabolism of theophylline, causing the theophylline to be metabolized slowly, and leading to increased blood concentrations. As discussed in the art, the area under the curve (AUC) for theophylline in patients co-administered allopurinol and theophylline has been reported to increase by up to 27%, the half-life increased by approximately 25%, and the clearance of theophylline may be decreased by 21% (Manfredi B A, et al., Clin. Pharmacol. Ther., 1981; 29(2), pp. 224-229). Accordingly, clinicians are required to alter the theophylline dosing and/or the allopurinol dosing in hopes of establishing a therapeutic dose for both disease states, while avoiding unwanted adverse effects that may result from increased theophylline concentrations.

Thus, in view of these considerations, there exists within the art a need to develop a treatment option for hyperuricemic patients that also suffer from respiratory disorders, whereby the clinician can administer typical dosing of theophylline without adjusting for adverse drug interactions.

SUMMARY

The present disclosure is directed to methods for treating hyperuricemia in patients requiring treatment with theophylline. The methods of the current invention avoid the drug interactions typically associated with theophylline administration and concomitant treatment with xanthine oxidase inhibitors.

In one embodiment, the present disclosure provides a method of treating hyperuricemia in a patient in need of treatment thereof, the method comprising the steps of: administering to the patient suffering from hyperuricemia and at least one secondary disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject is also receiving a concomitant administration of theophylline to treat the at least one secondary disease state; and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient does not result in theophylline toxicity to said patient; and (ii) administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The secondary disease state may include asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. As described in the method of this embodiment, the xanthine oxidoreductase inhibitor may include 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole and pharmaceutically acceptable salts thereof.

Moreover, the method of the current embodiment may include a theophylline dose ranging from about 95% to about 105%, and from about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. The method of the current invention may also include patients suffering from a third disease state, including gout, hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Further, the methods of the current embodiment include the treatment of hyperuricemia in patients that were previously receiving theophylline treatment prior to treatment with a xanthine oxidoreductase inhibitor.

In another embodiment, the current invention provides a method of treating hyperuricemia in a patient in need of treatment thereof, the method comprising the steps of: administering to the patient suffering from hyperuricemia and at least one second disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject will also be receiving a concomitant administration of theophylline to treat at least one second disease state, and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient will not result in theophylline toxicity to said patient; and (ii) administration of the theophylline will be in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The secondary disease state may include asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. As described in the method of this embodiment, the xanthine oxidoreductase inhibitor may include 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole and pharmaceutically acceptable salts thereof.

Moreover, the method of the current embodiment may include a theophylline dose ranging from about 95% to about 105%, and from about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. The method of the current invention may also include patients suffering from a third disease state, including gout, hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Further, the methods of the current embodiment include the treatment of hyperuricemia in patients that have not previously received theophylline treatment prior to treatment with a xanthine oxidoreductase inhibitor, and will begin treatment with both medications concurrently.

In yet another embodiment, the present disclosure provides a method of treating hyperuricemia in a patient suffering from gout and in need of treatment thereof, the method comprising the steps of: administering to the patient suffering from gout and hyperuricemia and at least one third disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject is also receiving a concomitant administration of theophylline to treat the at least one third disease state; and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient does not result in theophylline toxicity to said patient; and (ii) administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The third disease state may include asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. As described in the method of this embodiment, the xanthine oxidoreductase inhibitor may include 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole and pharmaceutically acceptable salts thereof.

Moreover, the method of the current embodiment may include a theophylline dose ranging from about 95% to about 105%, and from about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. The method of the current invention may also include patients suffering from a fourth disease state, including hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Further, the methods of the current embodiment include the treatment of hyperuricemia in patients suffering from gout and that were previously receiving theophylline treatment prior to treatment with a xanthine oxidoreductase inhibitor.

In another embodiment, the current invention provides a method of treating hyperuricemia in a patient suffering from gout and in need of treatment thereof, the method comprising the steps of: administering to the patient suffering from gout and hyperuricemia and at least one third disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject will also be receiving a concomitant administration of theophylline to treat at least one third disease state, and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient will not result in theophylline toxicity to said patient; and (ii) administration of the theophylline will be in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The third disease state may include asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. As described in the method of this embodiment, the xanthine oxidoreductase inhibitor may include 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole and pharmaceutically acceptable salts thereof.

Moreover, the method of the current embodiment may include a theophylline dose ranging from about 95% to about 105%, and from about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. The method of the current invention may also include patients suffering from a fourth disease state, including hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Further, the methods of the current embodiment include the treatment of hyperuricemia in patients that have not previously received theophylline treatment prior to treatment with a xanthine oxidoreductase inhibitor, and will begin treatment with both medications concurrently.

In still yet another embodiment, the present disclosure provides a method of treating a patient in need of treatment thereof, the method comprising the steps of: administering to the patient suffering from at least one first disease state and at least one secondary disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject is also receiving a concomitant administration of theophylline to treat the at least one secondary disease state; and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient does not result in theophylline toxicity to said patient; and (ii) administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The first disease state may include gout, prostatitis, inflammatory bowel disease, QT interval prolongation, myocardial infarction, cardiac hypertrophy, hypertension, nephrolithiasis, renal impairment, chronic kidney disease, metabolic syndrome, diabetes, diabetic nephropathy, congestive heart failure and combinations thereof.

The secondary disease state may include asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. As described in the method of this embodiment, the xanthine oxidoreductase inhibitor may include 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole and pharmaceutically acceptable salts thereof.

Moreover, the method of the current embodiment may include a theophylline dose ranging from about 95% to about 105%, and from about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. The method of the current invention may also include patients suffering from a third disease state, including gout, hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Further, the methods of the current embodiment include the treatment of the first disease state in patients that were previously receiving theophylline treatment prior to treatment with a xanthine oxidoreductase inhibitor.

BRIEF DESCRIPTION OF THE FIGURE

FIG. 1 shows the mean theophylline plasma concentration-time profiles following an oral dose of 400 mg theophylline coadministered with 80 mg of 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (also known as “febuxostat”) or matching placebo as described in Example 1.

DETAILED DESCRIPTION OF THE DISCLOSURE I. Definitions

Section headings as used in this section and the entire disclosure herein are not intended to be limiting.

As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9 and 7.0 are explicitly contemplated.

As used herein, the term “about” is used synonymously with the term “approximately.” Illustratively, the use of the term “about” indicates that values slightly outside the cited values, namely, plus or minus 10%. Such dosages are thus encompassed by the scope of the claims reciting the terms “about” and “approximately.”

As used herein, the term “AUC” refers to the area under the plasma concentration time curve of the active agent and which is calculated using the trapezoidal rule. The term “AUC_(t)” means the area under the plasma concentration time curve from time 0 to 120 hours after administration in units of ng·h/mL as determined using the trapezoidal rule. The term “AUC∞” means the area under the plasma concentration time curve from time 0 to infinite time. AUC∞ is calculated as AUC_(t)+LMT/(−β), where “LMT” is the last measurable plasma concentration and β is the terminal phase elimination rate constant. Unless otherwise noted herein, the reported value for the AUC is the central value of the AUC. The “central value” of the AUC is the mean AUC±standard deviation.

The terms “administer”, “administering”, “administered” or “administration” refer to any manner of providing a drug (such as, a xanthine oxidoreductase inhibitor or a pharmaceutically acceptable salt thereof) to a subject or patient. Routes of administration can be accomplished through any means known by those skilled in the art. Such means include, but are not limited to, oral, buccal, intravenous, subcutaneous, intramuscular, transdermal, by inhalation and the like.

The term “active agent” as used herein refers to (1) a xanthine oxidoreductase inhibitor or a pharmaceutically acceptable salt thereof or (2) a xanthine oxidase inhibitor or a pharmaceutically acceptable salt thereof. The term “active agent” and “drug” are used interchangeably herein. The solid state form of the active agent used in preparing the dosage forms of the present disclosure is not critical. For example, active agent used in preparing the modified release dosage forms of the present disclosure can be amorphous or crystalline. The final dosage form contains at least a detectable amount of crystalline active agent. The crystalline nature of the active agent can be detected using powder X-ray diffraction analysis, by differential scanning calorimetry or any other techniques known in the art.

The term “C_(max)” refers to the maximum observed plasma concentration of a xanthine oxidoreductase inhibitor or salt thereof produced by the ingestion of the dosage forms of the present disclosure. Unless otherwise noted herein, the reported value for the C_(max) is the central value of the C_(max). The “central value” of the C_(max) is the mean C_(max)±standard deviation.

The term “dosage form” refers to any solid object, semi-solid, or liquid composition designed to contain a specific pre-determined amount (i.e., dose) of a certain active agent. Suitable dosage forms may be pharmaceutical drug delivery systems, including those for oral administration, buccal administration, rectal administration, topical or mucosal delivery or subcutaneous implants, or other implanted drug delivery systems and the like. In one aspect, the dosage forms of the present disclosure are considered to be solid, however, they may contain liquid or semi-solid components. In another aspect, the dosage form is an orally administered system for delivering an active agent to the gastrointestinal tract of a subject. The dosage form of the present disclosure exhibit modified release of the active agent.

By an “effective amount” or a “therapeutically effective amount” of an active agent is meant a nontoxic but sufficient amount of the active agent to provide the desired effect. The amount of active agent that is “effective” will vary from subject to subject, depending on the age and general condition of the individual, the particular active agent or agents, and the like. Thus, it is not always possible to specify an exact “effective amount.” However, an appropriate “effective amount” in any individual case may be determined by one of ordinary skill in the art using routine experimentation. For example, the daily therapeutically effective or prophylactically effective amount of xanthine oxidoreductase inhibiting compounds administered to a patient in single or divided doses range from about 0.01 to about 750 milligram per kilogram of body weight per day (mg/kg/day). More specifically, a patient may be administered from about 5.0 mg to about 300 mg once daily, from about 20 mg to about 240 mg once daily and from about 40 mg to about 120 mg once daily of xanthine oxidoreductase inhibiting compounds. Of course, it will be understood by one skilled in the art that other dosage regimens may be utilized, such as dosing more than once per day, utilizing extended, controlled, or modified release dosage forms, and the like in order to achieve the desired result.

By “pharmaceutically acceptable,” such as in the recitation of a “pharmaceutically acceptable excipient,” or a “pharmaceutically acceptable additive,” is meant a material that is not biologically or otherwise undesirable, i.e., the material may be incorporated into a pharmaceutical composition administered to a patient without causing any undesirable biological effects.

The term “subject” refers to an animal. In one aspect, the animal is a mammal, including a human or non-human. The terms patient and subject may be used interchangeably herein.

The terms “treating” and “treatment” refer to reduction in severity and/or frequency of symptoms, elimination of symptoms and/or underlying cause, prevention of the occurrence of symptoms and/or their underlying cause, and improvement or remediation of damage. Thus, for example, “treating” a patient involves prevention of a particular disorder or adverse physiological event in a susceptible individual as well as treatment of a clinically symptomatic individual by inhibiting or causing regression of a disorder or disease.

As used herein, the term “xanthine oxidoreductase” refers to at least one form of xanthine oxidoreductase enzyme, namely xanthine oxidase and/or xanthine dehydrogenase.

As used herein, the phrase “xanthine oxidoreductase inhibitor” refers to any compound that (1) is an inhibitor of a xanthine oxidoreductase, such as, but not limited to, xanthine oxidase; and (2) chemically, does not contain a purine ring in its structure (i.e. is a “non-purine” analogue). The phrase “xanthine oxidoreductase inhibitor” as defined herein also includes metabolites, polymorphs, solvates and prodrugs of such compounds, including metabolites, polymorphs, solvates and prodrugs of the exemplary compounds described as Formula I and Formula II below. Examples of xanthine oxidoreductase inhibitors include, but are not limited to, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid and compounds having the following Formula I or Formula II:

wherein R₁ and R₂ are each independently a hydrogen, a hydroxyl group, a COOH group, an unsubstituted or substituted C₁-C₁₀ alkyl group, an unsubstituted or substituted C₁-C₁₀ alkoxy, an unsubstituted or substituted hydroxyalkoxy, a phenylsulfinyl group or a cyano (—CN) group;

wherein R₃ and R₄ are each independently a hydrogen or A, B, C or D as shown below:

wherein T connects or attaches A, B, C or D to the aromatic ring shown above at R₁, R₂, R₃ or R₄.

wherein R₅ and R₆ are each independently a hydrogen, a hydroxyl group, a COOH group, an unsubstituted or substituted C₁-C₁₀ alkyl group, an unsubstituted or substituted C₁-C₁₀ alkoxy, an unsubstituted or substituted hydroxyalkoxy, COO-Glucoronide or COO-Sulfate;

wherein R₇ and R₈ are each independently a hydrogen, a hydroxyl group, a COOH group, an unsubstituted or substituted C₁-C₁₀ alkyl group, an unsubstituted or substituted C₁-C₁₀ alkoxy, an unsubstituted or substituted hydroxyalkoxy, COO-Glucoronide or COO-Sulfate;

wherein R₉ is an unsubstituted pyridyl group or a substituted pyridyl group; and

wherein R₁₀ is a hydrogen or a lower alkyl group, a lower alkyl group substituted with a pivaloyloxy group and in each case, R₁₀ bonds to one of the nitrogen atoms in the 1,2,4-triazole ring shown above in Formula I.

wherein R₁₁ and R₁₂ are each independently a hydrogen, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted phenyl (the substituted phenyl in this Formula II refers to a phenyl substituted with a halogen or lower alkyl, and the like. Examples include, but are not limited to, p-tolyl and p-chlorophenyl), or R₁₁ and R₁₂ may together form a four- to eight-membered carbon ring together with the carbon atom to which they are attached;

wherein R₁₃ is a hydrogen or a substituted or unsubstituted lower alkyl group;

wherein R₁₄ is one or two radicals selected from a group consisting of a hydrogen, a halogen, a nitro group, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted phenyl (the substituted phenyl in this Formula II refers to a phenyl substituted with a halogen or lower alkyl group, and the like. Examples include, but are not limited to, p-tolyl and p-chlorophenyl), —OR₁₆ and —SO₂NR₁₇R_(17′), wherein R₁₆ is a hydrogen, a substituted or unsubstituted lower alkyl, a phenyl-substituted lower alkyl, a carboxymethyl or ester thereof, a hydroxyethyl or ether thereof, or an allyl; R₁₇ and R_(17′) are each independently a hydrogen or a substituted or unsubstituted lower alkyl group;

wherein R₁₅ is a hydrogen or a pharmaceutically active ester-forming group;

wherein A is a straight or branched hydrocarbon radical having one to five carbon atoms;

wherein B is a halogen, an oxygen, or an ethylenedithio;

wherein Y is an oxygen, a sulfur, a nitrogen or a substituted nitrogen;

wherein Z is an oxygen, a nitrogen or a substituted nitrogen; and

the dotted line refers to either a single bond, a double bond, or two single bonds (for example, when B is ethylenedithio, the dotted line shown in the ring structure can be two single bonds).

As used herein, the term “lower alkyl(s)” group refers to a C₁-C₇ alkyl group, including, but not limited to, including methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptal and the like.

As used herein, the term “lower alkoxy” refers to those groups formed by the bonding of a lower alkyl group to an oxygen atom, including, but not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, hexoxy, heptoxy and the like.

As used herein, the term “lower alkylthio group” refers to those groups formed by the bonding of a lower alkyl to a sulfur atom.

As used herein, the term “halogen” refers to fluorine, chlorine, bromine and iodine.

As used herein, the term “substituted pyridyl” refers to a pyridyl group that can be substituted with a halogen, a cyano group, a lower alkyl, a lower alkoxy or a lower alkylthio group.

As used herein, the term “four- to eight-membered carbon ring” refers to cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like.

As used herein, the phrase “pharmaceutically active ester-forming group” refers to a group which binds to a carboxyl group through an ester bond. Such ester-forming groups can be selected from carboxy-protecting groups commonly used for the preparation of pharmaceutically active substances, especially prodrugs. For the purpose of the present disclosure, said group should be selected from those capable of binding to compounds having Formula II wherein R₁₅ is hydrogen through an ester bond. Resultant esters are effective to increase the stability, solubility, and absorption in gastrointestinal tract of the corresponding non-esterified forms of said compounds having Formula II, and also prolong the effective blood-level of it. Additionally, the ester bond can be cleaved easily at the pH of body fluid or by enzymatic actions in vivo to provide a biologically active form of the compound having Formula II. Preferred pharmaceutically active ester-forming groups include, but are not limited to, 1-(oxygen substituted)-C₂ to C₁₅ alkyl groups, for example, a straight, branched, ringed, or partially ringed alkanoyloxyalkyl groups, such as acetoxymethyl, acetoxyethyl, propionyloxymethyl, pivaloyloxymethyl, pivaloyloxyethyl, cyclohexaneacetoxyethyl, cyclohexanecarbonyloxycyclohexylmethyl, and the like, C₃ to C₁₅ alkoxycarbonyloxyalkyl groups, such as ethoxycarbonyloxyethyl, isopropoxycarbonyloxyethyl, isopropoxycarbonyloxypropyl, t-butoxycarbonyloxyethyl, isopentyloxycarbonyloxypropyl, cyclohexyloxycarbonyloxyethyl, cyclohexyl methoxycarbonyloxyethyl, bornyloxycarbonyloxyisopropyl, and the like, C₂ to C₈ alkoxyalkyls, such as methoxy methyl, methoxy ethyl, and the like, C₄ to C₈ 2-oxacycloalkyls such as, tetrahydropyranyl, tetrahydrofuranyl, and the like, substituted C₈ to C₁₂ aralkyls, for example, phenacyl, phthalidyl, and the like, C₆ to C₁₂ aryl, for example, phenyl xylyl, indanyl, and the like, C₂ to C₁₂ alkenyl, for example, allyl, (2-oxo-1,3-dioxolyl)methyl, and the like, and [4,5-dihydro-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-1-yl]methyl, and the like.

In R₁₆ in Formula II, the term “ester” as used in the phrase “the ester of carboxymethyl” refers to a lower alkyl ester, such as methyl or ethyl ester; and the term “ether” used in the phrase “the ether of hydroxyethyl” means an ether which is formed by substitution of the hydrogen atom of hydroxyl group in the hydroxyethyl group by aliphatic or aromatic alkyl group, such as benzyl.

The carboxy-protecting groups may be substituted in various ways. Examples of substituents include halogen atom, alkyl groups, alkoxy groups, alkylthio groups and carboxy groups.

As used herein, the term “straight or branched hydrocarbon radical” in the definition of A in Formula II above refers to methylene, ethylene, propylene, methylmethylene, or isopropylene.

As used herein, the substituent of the “substituted nitrogen” in the definition of Y and Z in Formula II above are hydrogen, lower alkyl, or acyl.

As used herein, the term “phenyl-substituted lower alkyl” refers to a lower alkyl group substituted with phenyl, such as benzyl, phenethyl or phenylpropyl.

As used herein, the term “prodrug” refers to a derivative of the compounds shown in the above-described Formula I and Formula II that have chemically or metabolically cleavable groups and become by solvolysis or under physiological conditions compounds that are pharmaceutically active in vivo. Esters of carboxylic acids are an example of prodrugs that can be used in the dosage forms of the present disclosure. Methyl ester prodrugs may be prepared by reaction of a compound having the above-described formula in a medium such as methanol with an acid or base esterification catalyst (e.g., NaOH, H₂SO₄). Ethyl ester prodrugs are prepared in similar fashion using ethanol in place of methanol.

Examples of compounds having the above Formula I are: 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (also known as “febuxostat”), 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±) or 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole.

Preferred compounds having the above Formula I are: 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid. These preferred compounds have also been found not have an effect at a therapeutically effective amount in a subject on the activity of any of the following enzymes involved in purine and pyrimidine metabolism: guanine deaminase, hypoxanthine-guanine phosphoribosyltransferse, purine nucleotide phosphorylase, orotate phosphoribosyltransferase or orotidine-5-monophosphate decarboxylase (i.e., meaning that it is “selective” for none of these enzymes which are involved in purine and pyrimidine metabolism). Assays for determining the activity for each of the above-described enzymes is described in Yasuhiro Takano, et al., Life Sciences, 76:1835-1847 (2005). These preferred compounds have also been referred to in the literature as nonpurine, selective inhibitors of xanthine oxidase (NP/SIXO).

Examples of compounds having the above Formula II are described in U.S. Pat. No. 5,268,386 and EP 0 415 566 A1, and are incorporated, in their entirety, herein.

With the exception of pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±), methods for making xanthine oxidoreductase inhibiting compounds of Formulas I and II for use in the methods of the present disclosure are known in the art and are described, for example, in U.S. Pat. Nos. 5,268,386, 5,614,520, 6,225,474, 7,074,816 and EP 0 415 566 A1 and in the publications Ishibuchi, S. et al., Bioorg. Med. Chem. Lett., 11:879-882 (2001) and which are each herein incorporated by reference. Other xanthine oxidoreductase inhibiting compounds can be found using xanthine oxidoreductase and xanthine in assays to determine if such candidate compounds inhibit conversion of xanthine into uric acid. Such assays are well known in the art.

Pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±) is available from Otsuka Pharmaceutical Co. Ltd. (Tokyo, Japan) and is described in the following publications: Uematsu T., et al., “Pharmacokinetic and Pharmacodynamic Properties of a Novel Xanthine Oxidase Inhibitor, BOF-4272, in Healthy Volunteers, J. Pharmacology and Experimental Therapeutics, 270:453-459 (August 1994), Sato, S., A Novel Xanthine Deydrogenase Inhibitor (BOF-4272). In Purine and Pyrimidine Metabolism in Man, Vol. VII, Part A, ed. By P. A. Harkness, pp. 135-138, Plenum Press, New York. Pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±) can be made using routine techniques known in the art.

II. Methods of Treatment

The present disclosure relates to methods of treating hyperuricemia in patients that also require treatment with theophylline, without having to adjust the theophylline dose to account for the hyperuricemia treatment. Specifically, the present disclosure provides in one aspect, a method of treating hyperuricemia in a patient in need of treatment thereof, the method comprising the step of: administering to a patient suffering from hyperuricemia and at least one secondary disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject is also receiving a concomitant administration of theophylline to treat the at least one second disease state, and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient does not result in theophylline toxicity to said patient; and (ii) administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. More specifically, administration of the theophylline can be in an amount ranging from about 91% to about 109%, about 91% to about 108%, about 91% to about 107%, about 91% to about 106%, about 91% to about 105%, about 91% to about 104%, about 91% to about 103%, about 91% to about 102%, about 91% to about 101%, about 92% to about 109%, about 92% to about 108%, about 92% to about 107%, about 92% to about 106%, about 92% to about 105%, about 92% to about 104%, about 92% to about 103%, about 92% to about 102%, about 92% to about 101%, about 93% to about 109%, about 93% to about 108%, about 93% to about 107%, about 93% to about 106%, about 93% to about 105%, about 93% to about 104%, about 93% to about 103%, about 93% to about 102%, about 93% to about 101%, about 94% to about 109%, about 94% to about 108%, about 94% to about 107%, about 94% to about 106%, about 94% to about 105%, about 94% to about 104%, about 94% to about 103%, about 94% to about 102%, about 94% to about 101%, about 95% to about 109%, about 95% to about 108%, about 95% to about 107%, about 95% to about 106%, about 95% to about 105%, about 95% to about 104%, about 95% to about 103%, about 95% to about 102%, about 95% to about 101%, about 96% to about 109%, about 96% to about 108%, about 96% to about 107%, about 96% to about 106%, about 96% to about 105%, about 96% to about 104%, about 96% to about 103%, about 96% to about 102%, about 96% to about 101%, about 97% to about 109%, about 97% to about 108%, about 97% to about 107%, about 97% to about 106%, about 97% to about 105%, about 97% to about 104%, about 97% to about 103%, about 97% to about 102%, about 97% to about 101%, about 98% to about 109%, about 98% to about 108%, about 98% to about 107%, about 98% to about 106%, about 98% to about 105%, about 98% to about 104%, about 98% to about 103%, about 98% to about 102%, about 98% to about 101%, about 99% to about 109%, about 99% to about 108%, about 99% to about 107%, about 99% to about 106%, about 99% to about 105%, about 99% to about 104%, about 99% to about 103%, about 99% to about 102% or about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

In another aspect, the present disclosure provides a method of treating hyperuricemia in a patient in need of treatment thereof, the method comprising the step of: administering to a patient suffering from hyperuricemia and at least one secondary disease state, a therapeutically effective amount of at least one xanthine oxidoreductase inhibitor, wherein said subject will also be receiving a concomitant administration of theophylline (“will also be receiving” meaning such as, concurrently with the xanthine oxidoreductase inhibitor, or subsequent to the initiation of treatment with the xanthine oxidoreductase inhibitor) to treat the at least one second disease state, and further wherein (i) the administration of the at least one xanthine oxidoreductase inhibitor to said patient does not result in theophylline toxicity to said patient; and (ii) administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. More specifically, administration of the theophylline can be in an amount ranging from about 91% to about 109%, about 91% to about 108%, about 91% to about 107%, about 91% to about 106%, about 91% to about 105%, about 91% to about 104%, about 91% to about 103%, about 91% to about 102%, about 91% to about 101%, about 92% to about 109%, about 92% to about 108%, about 92% to about 107%, about 92% to about 106%, about 92% to about 105%, about 92% to about 104%, about 92% to about 103%, about 92% to about 102%, about 92% to about 101%, about 93% to about 109%, about 93% to about 108%, about 93% to about 107%, about 93% to about 106%, about 93% to about 105%, about 93% to about 104%, about 93% to about 103%, about 93% to about 102%, about 93% to about 101%, about 94% to about 109%, about 94% to about 108%, about 94% to about 107%, about 94% to about 106%, about 94% to about 105%, about 94% to about 104%, about 94% to about 103%, about 94% to about 102%, about 94% to about 101%, about 95% to about 109%, about 95% to about 108%, about 95% to about 107%, about 95% to about 106%, about 95% to about 105%, about 95% to about 104%, about 95% to about 103%, about 95% to about 102%, about 95% to about 101%, about 96% to about 109%, about 96% to about 108%, about 96% to about 107%, about 96% to about 106%, about 96% to about 105%, about 96% to about 104%, about 96% to about 103%, about 96% to about 102%, about 96% to about 101%, about 97% to about 109%, about 97% to about 108%, about 97% to about 107%, about 97% to about 106%, about 97% to about 105%, about 97% to about 104%, about 97% to about 103%, about 97% to about 102%, about 97% to about 101%, about 98% to about 109%, about 98% to about 108%, about 98% to about 107%, about 98% to about 106%, about 98% to about 105%, about 98% to about 104%, about 98% to about 103%, about 98% to about 102%, about 98% to about 101%, about 99% to about 109%, about 99% to about 108%, about 99% to about 107%, about 99% to about 106%, about 99% to about 105%, about 99% to about 104%, about 99% to about 103%, about 99% to about 102% or about 99% to about 101% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.

The method of the current invention comprises the co-administration of a xanthine oxidoreductase inhibitor and theophylline. The term xanthine oxidoreductase includes multiple therapeutic compounds, which have been described previously, and which are incorporated in their entirety herein. Generally, xanthine oxidoreductase inhibitors are compounds that inhibit the activity of xanthine oxidase, an enzyme involved in purine metabolism. In humans, inhibition of xanthine oxidase reduces the production of uric acid, which leads to secondary disease states such as gout, and other related diseases. Xanthine oxidoreductase inhibitors typically are classified as one of two types: purine analogues and non-purine analogues. The xanthine oxidoreductase inhibitors of the current invention include non-purine analogues, and, as noted previously, lack a purine ring in its chemical structure. In one embodiment, the xanthine oxidoreductase inhibitor includes, but is not limited to 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (also known as “febuxostat”), 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-(3-cyano-4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylic acid, 2-[4-(2-carboxypropoxy)-3-cyanophenyl]-4-methyl-5-thiazolecarboxylic acid, 1-(3-cyano-4-(2,2-dimethylpropoxy)phenyl)-1H-pyrazole-4-carboxylic acid, 1-3-cyano-4-(2,2-dimethylpropoxy)phenyl]-1H-pyrazole-4-carboxylic acid, pyrazolo[1,5-a]-1,3,5-triazin-4-(1H)-one, 8-[3-methoxy-4-(phenylsulfinyl)phenyl]-sodium salt (±) or 3-(2-methyl-4-pyridyl)-5-cyano-4-isobutoxyphenyl)-1,2,4-triazole. In another embodiment, the xanthine oxidoreductase inhibitor includes 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, 2-[3-cyano-4-(3-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, 2-[3-cyano-4-(2-hydroxy-2-methylpropoxy)phenyl]-4-methyl-5-thiazolecarboxylic acid, and pharmaceutically acceptable salts thereof. In a further embodiment, the xanthine oxidoreductase inhibitor is 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid and pharmaceutically acceptable salts thereof.

The phrase “pharmaceutically acceptable salt(s)”, as used herein, means those salts of compounds of the invention that are safe and effective for administration to a patient and that do not adversely affect the therapeutic qualities of the compound. Pharmaceutically acceptable salts include salts of acidic or basic groups present in compounds of the invention. Pharmaceutically acceptable acid addition salts include, but are not limited to, hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzensulfonate, p-toluenesulfonate and pamoate (i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)) salts. Certain compounds of the invention can form pharmaceutically acceptable salts with various amino acids. Suitable base salts include, but are not limited to, aluminum, calcium, lithium, magnesium, potassium, sodium, zinc, and diethanolamine salts. For a review on pharmaceutically acceptable salts see Berge et al., J. Pharm. Sci., 1977; 66:1-19, incorporated herein by reference, in its entirety.

One of skill in the art will also understand that the xanthine oxidoreductase inhibitors incorporated into the methods of the current invention may also incorporate pharmaceutically acceptable excipients. The dosage forms of the present disclosure will typically include pharmaceutically acceptable excipients. As is well known to those skilled in the art, pharmaceutical excipients are routinely incorporated into solid dosage forms to alter the physical and chemical characteristics of the dosage form. This is done to ease the manufacturing process as well as to improve the performance of the dosage form. Common excipients include, but are not limited to diluents, bulking agents, lubricants, binders, preservatives, antioxidants, and combinations thereof.

As used herein, the term “hyperuricemia” denotes a disease state in which the patient has as an elevation in serum urate (sUA) levels greater than or equal to 6.0 mg/dL in women and men. Many factors contribute to hyperuricemia, including: genetics, insulin resistance, hypertension, renal insufficiency, obesity, diet, use of diuretics, and consumption of alcoholic beverages. Causes of hyperuricemia can be classified into three functional types: increased production of uric acid, decreased excretion of uric acid, and mixed type, incorporating both of the previous etiologies. Increased production etiologies result from high levels of purine in the diet and increased purine metabolism. Decreased excretion etiologies result from kidney disease, certain drugs, and competition for excretion between uric acid and other molecules. Mixed causes include high levels of alcohol and/or fructose in the diet, and starvation. Hyperuricemia typically develops into gout when urate crystals are formed from supersaturated body fluids and deposited in joints, tophi, and parenchymal organs due to a disorder in the urate metabolism. Uric acid is the end product of purine metabolism and is generated in the cascade of hypoxantine→xanthine→uric acid.

In addition to suffering from hyperuricemia and at least one second disease state, the patients being treated according to the methods of the present disclosure may also be suffering from at least one third (or more) additional disease states. These third or more additional disease states include, but are not limited to, gout, hypertension, chronic stable angina, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof. Alternatively, the patients being treated according to the methods of the present invention may be suffering from both gout and hyperuricemia. In such instances, the patient will also be suffering from at least one third disease state. The patient is or will be concomitantly administered theophylline to treat the at least third disease state. The at least one third disease state includes, but is not limited to asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia and combinations thereof. In addition, the patient may also be suffering from at least one fourth (or more) additional disease states. These fourth or more additional disease states include, but are not limited to, hypertension, chronic stable angina, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof.

The methods of the current disclosure are directed to treating patients with secondary disease states that are indicated for, or require theophylline treatment. Theophylline is a methylxanthine compound used in the treatment of respiratory diseases resulting from airway constriction. Theophylline elicits a physiological response by two primary mechanisms, including competitive nonselective phosphodiesterase inhibitor, which raises intracellular cAMP, activates PKA, inhibits TNF-alpha and inhibits leukotriene synthesis, and reduces inflammation and innate immunity; and nonselective adenosine receptor antagonism, antagonizing A1, A2, and A3 receptors almost equally, which explains many of its cardiac effects and some of its anti-asthmatic effects. One skilled in the art will appreciate that the theophylline compound, as described herein is also known by its chemical name, 1,3-dimethyl-7H-purine-2,6-dione, its CAS Number, 58-55-9, and a multitude of brand name theophylline pharmaceutical products, incorporating theophylline as at least one of the active pharmaceutical ingredients. The theophylline component of the current methods also encompasses immediate release formulations, in addition to modified release formulations, including extended release, controlled release, and delayed release theophylline dosage forms. Dosage forms of theophylline may include tablets, capsules, sprinkle caps, liquid formulations, such as solutions and suspensions, and parenteral dosage forms including intravenous, intramuscular, intraarterial, intracerebral, intradermal, intrathecal, and intracerebral dosage forms, and subcutaneous dosage forms.

The methods of the current disclosure allow for theophylline to continue to be administered according to the manufacturer's suggested dosing of the compound. As used herein, the phrase “manufacturer's suggested dosing” signifies the dosing disclosed in the package insert of the theophylline dosage form and available in a variety of pharmaceutical treatment references. The methods of the current disclosure encompass the recommended dosing for all dosage forms, and include the treatment of all patients, for all disease states in which theophylline treatment may be effective. For example, a manufacturer's suggested dosing for oral theophylline may be 4-6 mg/kg. Thus, as described previously herein, in the present disclosure, administration of the theophylline is in an amount ranging from about 90% to about 110% of a manufacturer's recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor. If the manufacturer's suggested dosing is 4-6 mg/kg, about 90% to about 110% would be from about 3.6 to about 6.6 mg/kg.

The methods of the current disclosure are directed to treating hyperuricemia in patients having a secondary disease state that is indicated for, or is being treated with theophylline. The secondary disease states may include chronic obstructive pulmonary disease (COPD), chronic obstructive lung disease (COLD), chronic obstructive airway disease (COAD), chronic airflow limitation (CAL) and chronic obstructive respiratory disease (CORD), asthma, acute bronchitis, chronic bronchitis, emphysema, neonatal apnea, neonatal bradycardia, and combinations thereof. It is also contemplated that the patient requiring treatment for hyperuricemia may suffer from at least one additional disease state. Generally, the at least one additional disease state may be secondary to the patient's hyperuricemia, or may derive from an etiology unrelated to the hyperuricemia. Examples of the at least one additional disease state include, but are not limited to, gout, hypertension, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty arthritis, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof.

The methods of the current disclosure are based on the surprising findings that certain xanthine oxidoreductase inhibitors may be administered concomitantly with theophylline without adversely affecting blood serum levels and theophylline, and, consequently, avoiding the typical adjustment in dosing due to hyperuricemia treatment. Theophylline is metabolized by cytochrome P-450 (hereinafter “CYP 450”) to 1-methylxanthine, 3-methylxanthine, and 1,3-methyluric acid. Further, metabolism of 1-methylxanthine to 1-methyluric acid is mediated by xanthine oxidase. The xanthine oxidoreductase inhibitors described herein are not expected to have any inhibitory effect on CYP 450 involved in the metabolism of theophylline; however, because the xanthine oxidoreductase inhibitors are non-purine selective inhibitors of xanthine oxidase, it is generally expected that the compounds affect the xanthine oxidase mediate metabolism of theophylline and will decrease the clearance of theophylline, leading to increased theophylline serum levels. As stated previously, theophylline has a narrow therapeutic window, and even small increases in blood serum levels of the compound may result in serious adverse effects for the patient. However, the inventors surprisingly found that the administration of the xanthine oxidoreductase inhibitors described herein do not adversely affect theophylline serum levels, and that adjustment of theophylline treatment dosages is not required. Additional details pertaining to the pharmacokinetic parameters of the coadministration of a xanthine oxidoreductase inhibitor and theophylline are described in the Examples.

Prior to the discovery of the present invention, in previous studies using the xanthine oxidoreductase inhibitor febuxostat, subjects taking concomitant therapy with certain medications, including theophylline, could be enrolled in the study only if the certain excluded medication was discontinued for a certain length of time. For example, as shown in Table 1 below, febuxostat study F-GT06-153 specifically provided that subjects taking theophylline could not be enrolled in the study, unless the theophylline was discontinued at least 30 days prior to the day 1 randomization visit.

TABLE 1 Inclusion Criteria for Febuxostat Study F-GT06-153   “5.2.4 Prohibited Concomitant Therapy Subjects may not take any medication (other than study drug) for the purpose of lowering sUA levels. Subjects who have taken any of the excluded medications listed below, prior to the study, can be enrolled into the study if the excluded medication is discontinued at least 30 days prior to Day 1/Randomization Visit. The following medications are not to be administered 30 days prior or during the study: Any other urate-lowering drug, other than study drug; Use of NSAIDs and COX-2 inhibitors other than protocol required prophylaxis therapy (short-term use of NSAIDs and COX-2 inhibitors for treatment of gout flares is allowed); Salicylates (chronic use of aspirin ≦325mg/day is allowed); Thiazide diuretics; Losartan; Azathioprine; Mercaptopurine; Theophylline; IV Colchicine; Cyclosporine; Cyclophosphamide; Pyrazinamide; Sulfamethoxazole/trimethoprim; Use of corticosteroids (chronic prednisone ≦10mg/day or its equivalent and short-term use of higher doses of prednisone for treat- ment of gout flares is allowed); Changes in hormone replacement therapy or oral contraceptive therapy within 3 months of the Day 1/Randomization Visit or during the course of the study.”

As is evident from Table 1 above, the coadministration of theophylline and urate-lowering therapies is a significant clinical concern, and one that must be considered prior to initiation of urate-lowering therapies.

While hyperuricemia is one of the primary disease states treated by the xanthine oxidoreductase inhibitors discussed herein, one of skill in the art will appreciate that the methods of the current disclosure are equally applicable to other disease states that are typically treated by administration of one or more xanthine oxidoreductase inhibitors. These other disease states include, but are not limited to, gout, prostatitis, inflammatory bowel disease, QT interval prolongation, myocardial infarction, cardiac hypertrophy, hypertension, nephrolithiasis, renal impairment, chronic kidney disease, metabolic syndrome (also referred to as “Syndrome X” and includes, at least one of abdominal obesity, atherogenic dyslipidemia, insulin resistance, glucose intolerance, a prothrombotic state or a proinflammatory state), diabetes, diabetic nephropathy, congestive heart failure and combinations thereof (these conditions are sometimes collectively referred to herein as “at least one first disease state”). Accordingly, the current methods encompass treating a patient having one of the aforementioned at least one first disease state and also having a second disease state requiring theophylline treatment, through the administration of a xanthine oxidoreductase inhibitor without significant adjustment of the manufacturer's suggested dosing, and without inducing theophylline toxicity. Moreover, the current methods further encompass treating a patient having one of the aforementioned at least one first disease state, at least one second disease state requiring the theophylline treatment and at least one third disease state. In addition to suffering from hyperuricemia and at least one second disease state, the patients being treated according to the methods of the present disclosure may also be suffering from at least one third (or more) additional disease states. These third or more additional disease states include, but are not limited to, gout, hypertension, chronic stable angina, renal failure, nephrolithiasis, acute gouty arthritis, chronic gouty joint disease, tophaceous gout, uric acid urolithiasis, uric acid nephropathy, progressive renal disease, and combinations thereof.

By way of example, and not of limitation, examples of the present disclosure will now be given.

EXAMPLE 1 Effects of Multiple Febuxostat Doses on the Pharmacokinetics of Theophylline Administration

An experiment was performed to determine the effects of multiple doses of a xanthine oxidoreductase inhibitor, 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid, also known as “febuxostat”, on theophylline doses. The experiment was a phase I, double-blind, randomized, 2-period crossover study, in which 24 patients (12 male and 12 female) were enrolled in the study. Specifically, the total duration of the study was approximately 8 weeks (60 days), consisting of a Screening Period (Days-28 to −2), Check-in (Day-1) for Period 1, 7-day Treatment, a Washout Period (minimum of 7 days), Check-in for Period 2, 7-day Treatment, Study Exit or Early Termination, and a Follow-up phone call 10±2 days after the last dose of study medication. Subjects received both Regimens A and B in randomly assigned order. These regimens consisted of 7 daily doses of double-blind febuxostat 80 mg (A: two encapsulated febuxostat 40 mg tablets or B: matching placebo) and one dose (on Day 5 of each period) open-label theophylline 400 mg tablet.

On Days 1 to 7 of each period, subjects received febuxostat 80 mg or matching placebo at approximately 0900 hours after a minimum 10-hour fast, and followed 1 hour later by a standardized breakfast. On Day 5 of each period, subjects received a single oral dose of Uniphyl® (theophylline, anhydrous) 400 mg tablet along with the daily dose of febuxostat or matching placebo; food was first allowed 4 hours postdose. Water was available as desired, except for 1 hour before through 1 hour after study drug administration. Only 240 mL of water was allowed during dosing. Subjects were discharged in the morning of Day 8 of each Period (1 and 2), after plasma and urine pharmacokinetic sample collections and all study procedures were completed. For Day-1 of Period 2, subjects returned to the clinic after a minimum of 7 day washout period. For all subjects that completed both Periods 1 and 2 (or discontinued the study prematurely at an Early Termination visit, i.e., withdrew from study), a follow-up phone call was made 10±2 days after the last dose of study medication or Early Termination (ET). The effect of multiple oral doses of febuxostat on the pharmacokinetics of a single oral dose of theophylline were evaluated through measurement of plasma and urine concentration levels of theophylline at designated time points. Safety, tolerability, and theophylline toxicity were assessed throughout the study by monitoring adverse effects, clinical laboratory tests, vital signs, ECGs, and physical examination findings.

Theophylline plasma concentrations were determined from 7 mL blood samples obtained according to the schedules in Table 1 below. Trough febuxostat plasma concentrations were determined from 6 mL blood samples obtained according to the schedules in Table 2.

TABLE 2 Period 1 and 2: Blood Collection Schedules for Determination of Plasma Concentrations of Theophylline and Febuxostat Blood Sample Collection for Pharmacokinetics Theophylline Febuxostat Day 5 of Predose (up to 30 minutes Predose (up to 30 minutes Periods 1 and 2 prior to dosing [0 hour]) and at prior to dosing [0 hour]) 1, 2, 3, 4, 6, 8, 10, 12, and 14 hours postdose Day 6 of 16, 24, and 32 hours post Predose (up to 30 minutes Periods 1 and 2 Day 5 dosing prior to dosing [0 hour]) Day 7 of 40, 48, and 56 hours post None Periods 1 and 2 Day 5 dosing Day 8 of 64 and 72 hours post None Periods 1 and 2 Day 5 dosing

Additionally, to ensure that the drug plasma levels were not altered buy secondary conditions and medications, this experiment required subjects to abstain from the use of certain medications and other agents prior to and during the testing periods. The excluded medications and agents are summarized in Table 3 (prescription and nonprescription), including specifications on applicable time points through completion of all study activities.

TABLE 3 Excluded Medications and Agents 6 weeks prior 28 days prior 14 days prior 48 hours prior to Check-in to Check-in to Check-in to Check-in (Day-1) (Day-1) (Day-1) (Day-1) Nicotine- Prescription Foods or beverages Alcohol- containing medications containing grapefruit containing products or Seville oranges products Hormonal Over-the-counter Food or beverages contraception medications, containing caffeine (oral, patch, vitamins, herbal, or xanthine related implant, vaginal or dietary substances ring, or supplements injectable) Hormone Hepatic or Charbroiled foods replacement renal clearance therapy altering agents (erythromycin, cimetidine, barbiturates, phenothiazines, etc) Febuxostat or Allopurinol Note: excluded medications are from timepoints through completion of all study activities. Subjects were instructed not to take any medications or nonprescription drugs, vitamins, herbal supplements, or dietary supplements within 28 days prior to Check-in (Day-1).

The subjects of the current experiment were administered the appropriate dosage regimens and the pharmacokinetic data were evaluated. Mean plasma theophylline concentration vs. time profiles (linear and log-linear formats) for the two treatment regimens are depicted in FIG. 1. Additionally, individual and summary statistics of noncompartmental pharmacokinetic parameter estimates for theophylline following coadministration with febuxostat or placebo are presented in Table 4 below.

TABLE 4 Summary of Theophylline Pharmacokinetic Parameter Estimates Following an Oral Dose of 400 mg Theophylline Coadministered With 80 mg Febuxostat or Matching Placebo Tmax Cmax AUC(0-tlqc) AUC(0-inf)(a) T½(a) CL/F(a) Vz/F(a) (hr) (μg/mL) (μg · hr/mL) (μg · hr/mL) (hr) (mL/h) (mL) Theophylline + Febuxostat (Regimen A) N 23 23 23 18 18 18 18 Mean 8.43(b) 4.39 122 114 9.69(c) 4430 56900 SD 4.62 1.74 55.7 53.4 2.32 2370 20400 CV % 55 40 45 47 24 53 36 Theophylline + Placebo (Regimen B) N 23 23 23 18 18 18 18 Mean 7.05(b) 4.14 115 107 9.69(c) 4430 58200 SD 2.88 1.19 50.3 49.9 2.07 1930 17200 CV % 41 29 44 46 21 44 30 Regimen A: Febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5. Regimen B: Matching placebo for febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5. (a)The terminal phase of the pharmacokinetic profile of theophylline could not be adequately characterized in the remaining subjects. (b)Median Tmax values for Regimens A and B were 6.02 and 6.00 hr, respectively. (c)Harmonic mean T½ values for Regimens A and B were 9.13 and 9.28 hr, respectively.

As illustrated in Table 4 above, theophylline was absorbed with a mean T_(max) value of 7 to 9 hours (median=6 hours) and eliminated with a mean terminal half-life of 9.69 hours following oral administration of 400 mg theophylline with placebo or febuxostat. Mean theophylline C_(max) values were 4.14 and 4.39 μg/mL for subjects coadministered with placebo and febuxostat, respectively. Mean theophylline AUC(0-tlqc) values were 115 μg·hr/mL and 122 μg·hr/mL for subjects coadministered with placebo and febuxostat, respectively. Likewise, mean AUC(0-inf) values were also comparable between regimens. The intersubject variability (% CV) of C_(max) and AUC(0-tlqc) values of theophylline ranged from 29% to 40% and 44% to 45%, respectively. The estimated mean T_(1/2), CL/F, and V_(z)/F values for theophylline were generally similar between the 2 treatment regimens.

TABLE 5 Summary of Total Amount of Theophylline and Its Metabolites Excreted in Urine Over 72 Hours Following an Oral Dose of 400 mg Theophylline Coadministered With 80 mg Febuxostat or Matching Placebo Theophylline 1,3-Dimethyluric 1-Methyluric 1-Methylxanthine 3-Methylxanthine (mg) acid (mg) acid (mg) (mg) (mg) Theophylline + Febuxostat (Regimen A) N 23 23 23 23 23 Mean 35.0 105.2 3.1 40.1 26.9 SD 18.1 23.3 4.0 7.6 9.5 CV % 52 22 127 19 35 Theophylline + Placebo (Regimen B) N 23 23 23 23 23 Mean 35.0 114.8 56.2 0.1 30.9 SD 16.8 32.2 17.4 0.4 11.6 CV % 48 28 31 337 38 Regimen A: Febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5. Regimen B: Matching placebo for febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5.

As illustrated in Table 5 above, the mean amount of parent drug (i.e., theophylline) excreted in the urine over a 72 hour interval were comparable between regimen arms and consistent with the literature. See Melethil S et al., Res Commun Chem Pathol Pharmacol., 1982; 35(2):341-4. The mean amounts of 1,3-dimethyluric acid and 3-methylxanthine were also similar between the 2 regimens. In contrast, 1-methyluric acid decreased and 1-methylxanthine increased in subjects administered theophylline with febuxostat compared with those subjects administered theophylline with placebo.

A statistical analysis of the data was also performed. The effects of sequence, period, and regimen on theophylline T_(max), ln(C_(max)), ln(AUC[0-tlqc]), and ln(AUC[0-inf]) following coadministration of febuxostat or placebo were assessed. None of the aforementioned effects were statistically significant on the pharmacokinetic parameters (P>0.05) observed in the experiment. Further, the bioavailability of theophylline coadministered with febuxostat (Regimen A) relative to that of theophylline with placebo (Regimen B) was assessed via point estimates and 90% confidence intervals for the ratios of the central values for C_(max), AUC(0-tlqc), and AUC(0-inf), and is summarized in Table 6.

TABLE 6 Relative Bioavailability of Febuxostat Following Administration of a Single Oral Dose of 80 mg Febuxostat Parameter Point Estimate 90% Confidence Interval Regimen A vs Regimen B Cmax 1.03 (0.917, 1.149) AUC(0-tlqc) 1.04 (0.927, 1.156) AUC(0-inf) 1.05 (0.924, 1.189) Regimen A: Febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5. Regimen B: Matching Placebo for febuxostat 80 mg (two 40 mg encapsulated tablets) QD for 7 consecutive days and a single oral dose of theophylline, anhydrous 400 mg tablet on Day 5. Note: The point estimates and confidence intervals were obtained from the exponentiated results of analysis of the natural logarithm transformed data. From the statistical analyses of the pharmacokinetic data, the point estimates for theophylline C_(max), AUC(0-tlqc), and AUC(0-inf) were close to 100%, and the 90% confidence intervals for the ratios were within the bioequivalence limit of 0.80 to 1.25.

The results of this experiment showed that the maximum observed theophylline concentration (C_(max)) and exposure to theophylline (AUC) were comparable between treatment with febuxostat and treatment with placebo. Therefore, no adjustment of the theophylline dose was needed when coadministered with febuxostat. 

1. A method of co-administering febuxostat and theophylline to a hyperuricemic patient suffering from gout, the method comprising the steps of: administering to the hyperuricemic patient suffering from gout a therapeutically effective amount of febuxostat in a dose of 80 mg; and administering to the patient a therapeutically effective amount of theophylline subsequent to the administration of the febuxostat without adjusting the amount of theophylline administered for adverse drug interactions. 